1. Field of the Invention
The present invention relates to a positioning method of an optical element, a positioning member of the optical element and an optical unit using the optical element used for interconnection of a face light emitting laser array or an array type optical element, coupling between optical fibers for optical communication use, a collimate optical system, a micro lens in a neighboring field optical system in an optical memory and a micro lens array. Also, the present invention relates to a manufacturing method thereof.
2. Description of the Related Art
The technique for positioning and mounting an optical element such as a spherical lens on a predetermined substrate is disclosed, for example, in Japanese Unexamined Patent Publication No. 59-36214 and Japanese Examined Patent Publication No. 7-93457.
According to the technique disclosed in Japanese Unexamined Patent Publication No. 59-36214, a spherical lens is made to come into contact with sides (inclined planes) and bottom faces of V-shaped grooves formed on a substrate so as to position the spherical lens. According to the technique disclosed in Japanese Examined Patent Publication No. 7-93457, a spherical lens is positioned and supported as follows. Two V-shaped grooves are made to cross each other so that they can be formed into a T-shape. At the intersection of these V-shaped grooves, a spherical lens is contacted with two ridges which are formed when two sides (two inclined planes) of one V-shaped groove cross one side of the other V-shaped groove and also the spherical lens is contacted with a side of the other V-shaped groove which is opposed to the above two ridges. In this way, the spherical lens is positioned and supported.
According to the technique disclosed in Japanese Unexamined Patent Publication No. 59-36214, when the spherical lens is arranged in the V-shaped groove, it is possible to position the spherical lens in the width and the height direction of the V-shaped groove, however, it is impossible to position the spherical lens in the longitudinal direction of the V-shaped groove. Therefore, it is necessary to determine the most appropriate position by moving the spherical lens in the longitudinal direction of the V-shaped groove after the spherical lens has been arranged in the V-shaped groove, and this positioning work is complicated. Further, when the spherical lens is moved to the most appropriate position, there is a possibility that a shell-shape chipping is caused on the side of the V-shaped groove.
According to the technique disclosed in Japanese Examined Patent Publication No. 7-93457, it is necessary to form two V-shaped grooves on a substrate so that the two V-shaped grooves can cross each other like a T-shape. The only method of forming such a shape on the substrate is a method of anisotropic etching at present. Since the diameter of a spherical lens is usually 100 xcexcm to 1 mm, the depth of this V-shaped groove must be not less than 100 xcexcm. In the case where the V-shaped groove, the depth of which is not less than 100 xcexcm, is formed by means of anisotropic etching, a quantity of etching is so large that it is difficult to control the quantity of etching, that is, it is very difficult to form a V-shaped groove having an accurate profile, and further it takes a very long time for etching. For the above reasons, it has been recently difficult to position a spherical lens with high accuracy of not more than several xcexcm.
The present invention has been accomplished in view of the above circumstances. It is an object of the present invention to provide a positioning method of an optical element, a positioning device and an optical element and a manufacturing method thereof by which the optical element such as a spherical lens can be positioned with high accuracy not more than several xcexcm.
In order to solve the above problems, the first aspect is a positioning method of an optical element for positioning the optical element by arranging the optical element at an intersection of V-shaped grooves which are formed on a surface of a substrate and cross each other, characterized in that: when the optical element is arranged at the intersection of the V-shaped grooves, the optical element is supported by four points of contact at which four ridges formed in the intersection and a surface of the optical element come into contact with each other so that the optical element is three-dimensionally positioned.
The second aspect is a positioning method of an optical element according to the first means, wherein the V-shaped grooves are formed by means of machining.
The third aspect is a positioning method of an optical element according to the second means, wherein the V-shaped grooves are formed by means of formed tool grinding in which a formed grinding tool is used.
The fourth aspect is a positioning method of an optical element according to one of the first, second and third means, wherein the optical element is a spherical lens.
The fifth aspect is a positioning member of an optical element characterized in that: V-shaped grooves are formed on a surface of a substrate; and the optical element is positioned when the optical element is supported at our points on four ridges formed in an intersection of the V-shaped grooves.
The sixth aspect is a positioning member of an optical element according to the fifth aspect, wherein the intersection of the V-shaped grooves is formed into an array-shape.
The seventh aspect is a positioning member of an optical element according to the fifth or the sixth aspect, wherein the substrate is made of glass.
The eighth aspect is an optical unit comprising: a substrate, on the surface of which V-shaped grooves crossing each other are formed; and an optical element positioned and fixed when it is supported at four points on four ridges formed in the intersection of the V-shaped grooves.
The ninth aspect is an optical unit according to the eighth aspect, wherein an opening for making a beam of light to be incident on or emergent from the optical element is formed on the substrate.
The tenth aspect is an optical unit according to the eighth or ninth aspect, wherein the optical element is a spherical lens.
The eleventh aspect is an optical unit according to one of the eighth, ninth and tenth aspect, characterized in that: one of the substrate and the optical element or both the substrate and the optical element are made of glass.
The twelfth aspect is an optical unit according to one of the eighth, ninth, tenth and eleventh aspect, wherein the three-dimensional positional accuracy of the optical element is in a range xc2x15 xcexcm.
The thirteenth aspect is a manufacturing method of an optical unit comprising the steps of:
a positioning step for positioning an optical element when the optical element is supported at four points on four ridges formed in an intersection of the V-shaped grooves; and
a fixing step for fixing the optical element, which has been positioned in the positioning step, at the substrate or an optical element fixing member except for the substrate.
The fourteenth aspect is a manufacturing method of an optical unit comprising the steps of:
a positioning step for positioning an optical element when the optical element is supported at four points on four ridges formed in an intersection of the V-shaped grooves;
a fixing step for fixing the optical element, which has been positioned in the positioning step, at the substrate or an optical element fixing member except for the substrate; and
an opening forming step for forming an opening by removing a portion of the substrate so that a beam of light can be incident on or emergent from the optical element.
The fifteenth aspect is a manufacturing method of an optical unit according to the thirteenth aspect or the fourteenth aspect, wherein the V-shaped grooves are formed by means of machining.
The sixteenth aspect is a manufacturing method of an optical unit according to one of the thirteenth, the fourteenth and the fifteenth aspect, wherein the V-shaped grooves are formed by means of formed tool grinding in which a formed grinding tool is used.
The seventeenth aspect is a manufacturing method of an optical unit according to one of the thirteenth, the fourteenth, the fifteenth and the sixteenth aspect, wherein the optical element is a spherical lens.
The eighteenth aspect is a manufacturing method of an optical unit in which a hemispherical or super hemispherical optical elements are held, comprising the steps of:
a positioning step for positioning an optical element when the optical element is supported at four points on four ridges formed in an intersection of V-shaped grooves of a substrate, which cross each other on a surface of the substrate;
a fixing step for housing at least a part of the upper portion of the optical element, which has been positioned in said positioning step, in a housing hole of a hole array substrate, of which the diameter is larger than that of said optical element, and fixing said optical element on side surfaces of said housing hole; and
a lens grinding step, wherein after said substrate is removed, the exposed portion of the optical element that has been fixed onto said hole array substrate is ground and removed.
The nineteenth aspect is a manufacturing method of an optical unit, wherein said substrate has through-holes communicating with the substrate rear surface at said V-shaped grooves, and at least said fixing step includes a step of giving vacuum from said through-holes.
The twentieth aspect is lens chip characterized in that it is manufactured by diving the optical unit having the plural optical elements, which has been manufactured by the manufacturing method of the optical unit according to fourteenth aspect.
The twenty first aspect is a lens chip characterized in that it is manufactured by diving the optical unit having the plural optical elements, which has been manufactured by the manufacturing method of the optical unit according to the eighteenth aspect.
The twenty second aspect is a floating-type head for optical memory medium having an optical system including a lens chip for optically reading data recorded on an optical memory medium by running on the optical memory medium floatingly, characterized by being manufactured using the lens chip according to the twenty first aspect as said lens chip.